Type inference is really useful in writing less and clean code. But how about the compilation time especially in large projects. Isn't it better to use specific type declaration than type inference in order for your project to build faster?
Type inference - Compilation time
Explicit type declaration is useful in complex formulas. You may even sometime get a compiler complain "expression too complex" because of this.
So, that shows that type inference does add overhead to compilation (not to build).
In addition, unless for vey trivial declarations like
let val = 10
I find it a good practice to explicit type.
Anyway, at the end, do you see a compilation speed problem ? If not, it is your personal choice.
So, that shows that type inference does add overhead to compilation (not to build).
In addition, unless for vey trivial declarations like
let val = 10
I find it a good practice to explicit type.
Anyway, at the end, do you see a compilation speed problem ? If not, it is your personal choice.
I had read this article (linkedin.com/pulse/faster-swift-builds-leaving-type-inference-behind-dan-zinngrabe) in the past about type inference and when I saw this wwdc20 video I was expecting to find something more concrete on how type inference affects compilation time.
Sadly, there wasn't such reference so I guess it's up to each one of us to choose which path to follow.
Sadly, there wasn't such reference so I guess it's up to each one of us to choose which path to follow.
You're right that when you rely on type inference, the compiler is doing more work on your behalf. In most cases, this extra work to perform type inference doesn't take a significant amount of compilation time, but there are a number of cases where you can run into performance issues with type inference - most notably in expressions with many chained operators and numeric literals.
If the compiler is taking too long to infer types in your code, you'll see the error message the compiler is unable to type-check this expression in reasonable time; try breaking up the expression into distinct sub-expressions. Please file a bug report using Feedback Assistant if you ever experience performance issues with type inference. However, this error message can always be worked around either by breaking up the expression into a number of smaller expressions as the message suggests, or by providing more explicit type annotations in the expression.
If the compiler is taking too long to infer types in your code, you'll see the error message the compiler is unable to type-check this expression in reasonable time; try breaking up the expression into distinct sub-expressions. Please file a bug report using Feedback Assistant if you ever experience performance issues with type inference. However, this error message can always be worked around either by breaking up the expression into a number of smaller expressions as the message suggests, or by providing more explicit type annotations in the expression.
Why do you really care about it ? Do you meet performance issues ?
There cannot be a general formula on how type inference affects compilation time, because it is involving some tree exploration.
There cannot be a general formula on how type inference affects compilation time, because it is involving some tree exploration.